22 SEXUAL SELECTION. [Part IL 



characters, the males originally varied, with their varia- 

 tions transmitted to the same sex, and accumulated 

 through sexual selection by attracting or exciting the fe- 

 males. In many cases, however, such characters have 

 been transferred, either partially or completely, to the 

 females. In other cases, again, both sexes have been col- 

 ored alike for the sake of protection ; but in no instance 

 does it appear that the female alone has had her colors or 

 other characters specially modified for this purpose. 



The last point which need be noticed is that in many 

 parts of the world fishes are known to make peculiar 

 noises, which are described in some cases as being musi- 

 cal. Very little has been ascertained with respect to the 

 means by which such sounds are produced, and even less 

 about their jjurpose. The drumming of the Umbrinas in 

 the Europeain seas is said to be audible from a depth of 

 twenty fathoms. The fishermen of Rochelle assert " that 

 the males alone make the noise during the spawning-time ; 

 and that it is possible, by imitating it, to take them with- 

 out bait." " If this statement is trustworthy, we have an 

 instance in this, the lowest class of the Vertcbrata, of 

 what we shall find prevailing throughout the other verte- 

 bi'ate classes, and which prevails, as we have already seen, 

 with insects and spiders ; namely, that vocal and instru- 

 mental sounds so commonly serve as a love-call or as a 

 love-charm, that the power of producing them was proba- 

 bly first developed in connection with liie propagation of 

 the species. 



Amphibians. 



TIrodela. — First for the tailed amphibians. The sexes 

 of salamanders or newts often difter much both in color 

 and structure. In some species prehensile claws are de- 

 veloped on the fore-legs of the males during the breeding- 

 s'" Tlic Rev. C. Kingsley, in 'Nature,' Ma.v, ISVO, p. 40. 



